1). Field of the Invention
Embodiments of this invention relate to a polymer device and a method of constructing a polymer device.
2). Discussion of Related Art
Polymer devices, such as ferroelectric polymer memory chips, like other integrated circuits, are formed on semiconductor wafers. A lower set of electrodes is formed on the insulating layer over which a polymer layer is then deposited. An upper set of electrodes is then formed on the polymer layer. Memory cells are formed in the polymer where the upper electrodes pass over the lower electrodes.
The conductive materials, typically metals, used in the electrodes are highly reactive with the polymer under operating conditions. If polymer and the metals make contact, a chemical reaction may begin under operating conditions which leads to the failure of the device. Additionally, the metal used on the electrodes slowly migrates into the polymer, which increases the difficulty in distinguishing the “1 state” of the memory cells from the “0 state” of the memory cells. It is believed that the degradation arises after repeated use as the capacitance of polymer increases as anions from the electrodes migrate into the polymer.
One solution to preventing the electrodes from contacting the polymer is to form an interface, or barrier layer, between the electrodes and the polymeric layer to prevent such migration and the chemical reaction from taking place. However, the use of typical interface layers a further hampers the performance of the memory cells. Another solution is to use a conductive polymer layer as the interface layer. However, in order for this approach to work, the conductive polymer must be patterned to match the electrodes and at this point there is no way to do so efficiently.